September 24, 2024, 04:31:59 AM
Forum Rules: Read This Before Posting


« previous next »
Pages: [1]   Go Down

Topic: Mass percent and density question?  (Read 7634 times)

0 Members and 1 Guest are viewing this topic.

Offline michaelt817

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +1/-0
Mass percent and density question?
« on: August 29, 2010, 07:57:10 PM »
The legal limit for human exposure to carbon monoxide in the workplace is 35 ppm. Assuming that the density of air is 1.3g/L, how many grams of carbon monoxide are in 1.0 L of air at the maximum allowable concentration.

Not sure where to start... Any tips would be greatly appreciated!
Logged

Offline MrTeo

  • Chemist
  • Full Member
  • *
  • Posts: 312
  • Mole Snacks: +31/-9
  • Gender: Male
Re: Mass percent and density question?
« Reply #1 on: August 30, 2010, 02:30:59 AM »
What does ppm mean?
Logged
The way of the superior man may be compared to what takes place in traveling, when to go to a distance we must first traverse the space that is near, and in ascending a height, when we must begin from the lower ground. (Confucius)

Offline michaelt817

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +1/-0
Re: Mass percent and density question?
« Reply #2 on: September 01, 2010, 06:37:47 PM »
parts per million
Logged

Offline cswarth

  • Regular Member
  • ***
  • Posts: 10
  • Mole Snacks: +0/-0
Re: Mass percent and density question?
« Reply #3 on: September 01, 2010, 07:37:27 PM »
I think even I can answer this one....

Assuming they measure ppm as a function of mass (and not volume) then it's simple.
You want t get how may grams CO are permissible in a liter of air.  They tell you how much a liter of air weighs (1.3G/L) and they tell you how much of that can be CO by weight (35/1000000).

You can use unit analysis to make sure the answer makes sense.

(Liters of air) x (grams of air)/(liter of air) x (grams CO)/(grams of air) = grams of CO


Logged
Pages: [1]   Go Up
« previous next »
Sponsored Links